After a date, that we have early at morning, a girl wrote me that sentence. What does it mean? I cannot figure out the sense translating it into my mother tongue. Thank you all.
It means she was very pleased with how things went when you were together.
There are many English expressions about feeling light or floating. They usually mean that the person is very happy about something. They are most often used when something unusual has happened to abruptly change your mood. Especially when things previously were not nearly as pleasing.
Compare such expressions as:
"A load off my mind" meaning, some thought has been bothering me and now it is not bothering me, so I feel much lighter. "Getting a passing grade on the test was a load off my mind."
"With a light heart" meaning something is causing me to feel good or happy and so it is like my heart is light. "It was with a light heart that I started my hike on the very pleasant and sunny day."
"With a spring in my step" meaning I feel happy, especially for some short-term or unusual reason, and so I tend to have that show in my movements, and so I tend to bounce when I walk. "I exited the successful job interview with a spring in my step."
The negative sense is also very common. If you are sad or disappointed, you might express it as having a heavy heart, being downcast, or as being weighed down by your thoughts.